Google has advised that I have an unsafe implementation of the interface X509TrustManager in my Android application and need to change my code as follows:
If you encounter this from external library you're using, check if appache libraray is the cause of it.
For me apache library caused the error : i was using deprecated class - MultipartEntity. This class uses SSLContextBuilder which uses TrustManagerDelegate. TrustManagerDelegate implements X509TrustManager, which cause "unsafe implementation of TrustManager" error when uploading application to google play store.
The solution is : instead of deprecated MultipartEntity class, use MultipartEntityBuilder.
For example :
MultipartEntity httpMultipart = new MultipartEntity();
String contentType = httpMultipart.getContentType().getValue();
Will be replaced by :
MultipartEntityBuilder httpMultipart = new MultipartEntityBuilder();
String contentType = httpMultipart.build().getContentType().getValue();